1. Field of the Invention
Artificial blood compositions are prepared from certain perfluoro chemicals in physiological saline using certain polyoxybutylene-polyoxyethylene block copolymers. These clock copolymers provide stable emulsions.
2. Description of the Prior Art
In an article by Irving R. Schmolka entitled, "Introduction to Artificial Blood Materials", from session 1 of a symposium on artificial blood presented at the Blood Resource Branch for National Heart and Lung Institute, NIH, Bethesda, Maryland, April 5-6, 1974, polyoxypropylene-polyoxyethylene block polymers are disclosed as being useful emulsifiers for perfluoro chemicals in synthetic blood preparations.
The HS symposium, "Research in Perfluoro Chemicals in Medicine Biology", Apr. 28-29, 1977 at Karolinska Institute Research Center, Huddinge University Hospital in Huddinge, Sweden, was directed to fluoro chemicals, in particular perfluorodecalin. A paper related to emulsions with polyoxypropylene-polyoxyethylene block copolymer emulsifiers. Although it is possible to emulsify perfluorodecalin in physiological saline, using a block polymer of ethylene and propylene oxides, the resulting emulsion is not stable. The reference relates to the use of a blend of perfluorodecalin and perfluorotripropylamine (FTPA) in artificial blood preparations to overcome the emulsion instability. Unfortunately, the FTPA has a low vapor pressure and accumulates in the liver which is not desirable.
U.S. Pat. No. 4,110,474 relates to perfluorinated 2,2,4,4-tetramethylpentane useful in synthetic blood substitute compositions. The use of polyoxybutylene-polyoxyethylene block copolymers as emulsifiers is not mentioned.
U.S. Pat. No. 4,105,798, Moore et al, Aug. 8, 1978, relates to perfluorinated compounds useful in synthetic blood in perfusion media. Polyoxybutylene-polyoxyethylene block copolymers are not mentioned as emulsifiers.
Both patent reference U.S. Pat. Nos. 4,105,798 and 4,110,474 utilize a polyoxypropylene-polyoxyethylene block copolymer known as PLURONIC F68. Some of the problems utilizing this copolymer are enumerated above. This invention is directed towards stable emulsions of perfluoro chemicals devoid of the prior art problems.